That’s the analogy Wall Street observers fear will best describe Citigroup in a few weeks when the federal government completes its bank stress test.

At a time when rivals like JPMorgan, Wells Fargo and others are showing signs of a comeback, there is increasing worry that Citi will find itself ranked at the bottom of a test in which no bank is technically expected to fail.

The Federal Reserve, the Treasury and other regulators are conducting the stress tests in an attempt to determine the safety and soundness of the nation’s 19 largest financial institutions and to bolster the market’s confidence in the banking industry.

Sources told The Post that banks examined as part of the stress test are expected to be assigned one of three rankings: top tier institutions that are capable of operating even in the most dour conditions, those that aren’t and those that fit somewhere in the middle.

Christopher Whalen, co-founder of risk-advisory firm Institutional Risk Analytics, believes that Citi may fall dead last among the 19 banks given its outsize consumer debt exposure.

Whalen argues that Citi should be forced to restructure with bondholders converting their positions into equity to prevent matters from getting worse.

He fears that Citi will “chew through” its rescue funds because its loss rates and expenses are comparatively higher than its peers.

“Clearly, Citi is among the banks that will come in with the worst results,” Whalen added. “The problems is, I get the sense that the regulators don’t have a plan [of action] to go along with the results.”

So far this week, banking giants Goldman Sachs and JPMorgan have reported better-than-expected profits and have hinted that the worst of the economic storm might be behind them.

What’s more, though Citi is widely seen as the definition of a troubled bank and received $45 billion in rescue cash, there is some speculation Citi might eke out a small first-quarter profit when it reports this morning.

However, some market players continue to express concerns about Citi’s capital adequacy in the face of severe headwinds buffeting the financial sector.

With the outlook for financials getting more harrowing since talks of the tests were floated, it’s the next several months that are causing some hand-wringing.

What’s unclear at this point is how much the regulators will disclose to the public about the performance of a specific bank, given the damaging effect such information could have on the market.

The Treasury and Fed, however, are expected to publish their analysis methods and market assumptions applied to the test on April 24.

And there were reports out saying the results could be announced in some fashion on May 4. Those results may not be made public, but that issue is being debated in Washington.